It's hard to tell TBO. HOX has great build quality and finish while SGS3 is packed with great new features. HTC introduced the ONE series first (first quadcore phone). So probably they have the advantage here

The One X has a really good camera, with all sorts of lenses, modes, and features. The GS3 has S Voice, which is also really useful. Here in America, I think that the S3 is doing better because more people know about it and it is being marketed better. Personally, I have the One X and I love it.